Light-emitting device having light-emitting elements connected in series

• US 7,956,367 B2
• Filed: 02/12/2007
• Issued: 06/07/2011
• Est. Priority Date: 08/29/2002
• Status: Active Grant

• Current Assignee: Seoul Semiconductor Co., Ltd.
• Original Assignee: Seoul Semiconductor Co., Ltd.
• Inventors: Ao, Jin-Ping, Ono, Yasuo, Sakai, Shiro
• Primary Examiner(s): Andújar; Leonardo
• Assistant Examiner(s): Roland; Christopher M
• Application Number:
  US11/705,205
• Publication Number:
  US 20070138500A1
• Time in Patent Office: 1,576 Days
• Field of Search: 257 12- 13, 257/79, 257 82- 85, 257 88- 90, 257 92- 95, 257 96- 97, 257/103, 257/E51.022, 257/E21.381, 257/164, 257/E33.065, 257/E27.051, 257/E27.073, 257/E25.019, 257/E25.02, 315/185.S, 315/200.A, 315/247, 315312-320, 315/322, 315/326, 327/493, 327/494, 327/495, 327/496, 327/503, 327/504, 327/514, 327/515, 345/82, 362/555, 362/612
• US Class Current: 257/90
• CPC Class Codes: H01L 2224/24 of an individual high density interconnect connector
• CPC Class Codes: H01L 27/15 including semiconductor components having potential barriers, specially adapted for light emission
• CPC Class Codes: H01L 27/153 in a repetitive configuration, e.g. LED bars
• CPC Class Codes: H01L 27/156 two-dimensional arrays
• CPC Class Codes: H01L 33/08 with a plurality of light emitting regions, e.g. laterally discontinuous light emitting layer or photoluminescent region integrated within the semiconductor body H01L27/15 takes precedence
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01L 33/38 with a particular shape
• CPC Class Codes: H01L 33/42 Transparent materials
• CPC Class Codes: H01L 33/62 Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls

Abstract

A light-emitting device operating on a high drive voltage and a small drive current. LEDs (1) are two-dimensionally formed on an insulating substrate (10) of e.g., sapphire monolithically and connected in series to form an LED array. Two such LED arrays are connected to electrodes (32) in inverse parallel. Air-bridge wiring (28) is formed between the LEDs (1) and between the LEDs (1) and electrodes (32). The LED arrays are arranged zigzag to form a plurality of LEDs (1) to produce a high drive voltage and a small drive current. Two LED arrays are connected in inverse parallel, and therefore an AC power supply can be used as the power supply.

Claims

1. A light emitting device having a plurality of GaN-based light emitting diode elements formed on a single insulating substrate, wherein

the plurality of light emitting diode elements are arranged in a two-dimensional pattern on the insulating substrate;

the plurality of light emitting diode elements are grouped into a first group and a second group of equal number, the first and second groups being connected between two electrodes for AC power supply in parallel so that the first group and the second group are of opposite polarities, and each of the first group and the second group of light emitting diode elements being placed in a zigzag pattern; and

a negative electrode of one of the light emitting diode elements of the first group other than the light emitting diode element at the end of the first group is shared as and is electrically connected to a negative electrode of one of the light emitting diode elements of the second group,

wherein each of the plurality of light emitting diode elements has a planar shape of an approximate triangle, and

wherein the one of the light emitting diode elements of the first group and the one of the light emitting diode elements of the second group are placed in such a manner that the two light emitting diode elements as a whole have an approximate square shape and share a negative electrode at opposing sides.

2. The light emitting device according to claim 1, wherein the plurality of light emitting diode elements are of approximately same shape and of approximately same size.

3. The light emitting device according to claim 1, wherein all light emitting diode elements of the first group of light emitting diode elements are connected in series between the two electrodes of the AC power supply.

4. The light emitting device according to claim 3, wherein all light emitting diode elements of the second group of light emitting diode elements are connected in series between the two electrodes of the AC power supply.

5. The light emitting device according to claim 1, wherein the first group of light emitting diode elements comprises a first set and a second set of light emitting diode elements, the second group of light emitting diode elements comprises a third set and a fourth set of light emitting diode elements, and the third set of light emitting diode elements is disposed between the first set of light emitting diode elements and the second set of light emitting diode elements, and wherein a negative electrode of one of the light emitting diode elements of the first set of light emitting diode elements is shared as and is electrically connected to a negative electrode of one of the light emitting diode elements of the third set of light emitting diode elements.

6. The light emitting device according to claim 1, wherein the first group and second group of light emitting diode elements each comprise at least three rows of light emitting diode elements.

7. A light emitting device having a plurality of GaN-based light emitting diode elements formed on a single insulating substrate, wherein

the plurality of light emitting diode elements are arranged in a two-dimensional pattern on the insulating substrate;

the plurality of light emitting diode elements are grouped into a first group and a second group of equal number, the first and second groups being connected between two electrodes for AC power supply in parallel so that the first group and the second group are of opposite polarities, and each of the first group and the second group of light emitting diode elements being placed in a zigzag pattern; and

a negative electrode of one of the light emitting diode elements of the first group other than the light emitting diode element at the end of the first group is shared as and is electrically connected to a negative electrode of one of the light emitting diode elements of the second group,

wherein the first group of light emitting diode elements comprises a first set and a second set of light emitting diode elements, the second group of light emitting diode elements comprises a third set and a fourth set of light emitting diode elements, the third set of light emitting diode elements is disposed between the first set of light emitting diode elements and the second set of light emitting diode elements, and the second set of light emitting diode elements is disposed between the third set of light emitting diode elements and the fourth set of light emitting diode elements, and

wherein a negative electrode of one of the light emitting diode elements of the first set of light emitting diode elements, a positive electrode of one of the light emitting diode elements of the second set of light emitting diode elements, a positive electrode of one of the light emitting diode elements of the third set of light emitting diode elements, and a negative electrode of one of the light emitting diode elements of the fourth set of light emitting diode elements are shared as and are electrically connected to each other.

8. The light emitting device according to claim 7, wherein each of the plurality of light emitting diode elements has a planar shape of an approximate square and the plurality of light emitting diode elements are arranged in a matrix form.

9. The light emitting device according to claim 7, wherein the first group of light emitting diode elements further comprises a fifth set of light emitting diode elements, the second group of light emitting diode elements further comprises a sixth set of light emitting diode elements, the fourth set of light emitting diode elements is disposed between the second set of light emitting diode elements and the fifth set of light emitting diode elements, and the fifth set of light emitting diode elements is disposed between the fourth set of light emitting diode elements and the sixth set of light emitting diode elements, and

wherein a negative electrode of one of the light emitting diode elements of the second set of light emitting diode elements, a positive electrode of one of the light emitting diode elements of the fourth set of light emitting diode elements, a positive electrode of one of the light emitting diode elements of the fifth set of light emitting diode elements, and a negative electrode of one of the light emitting diode elements of the sixth set of light emitting diode elements are shared as and are electrically connected to each other.

10. The light emitting device according to claim 9, wherein each set of light emitting diode elements is individually disposed in a straight line on the insulating substrate.

11. The light emitting device according to claim 9, wherein a negative electrode of one of the light emitting diode elements of the first set of light emitting diode elements, a positive electrode of one of the light emitting diode elements of the second set of light emitting diode elements, a positive electrode of one of the light emitting diode elements of the third set of light emitting diode elements, and a negative electrode of one of the light emitting diode elements of the fourth set of light emitting diode elements are shared as and are electrically connected to each other via a first air bridge line, and

wherein a negative electrode of one of the light emitting diode elements of the second set of light emitting diode elements, a positive electrode of one of the light emitting diode elements of the fourth set of light emitting diode elements, a positive electrode of one of the light emitting diode elements of the fifth set of light emitting diode elements, and a negative electrode of one of the light emitting diode elements of the sixth set of light emitting diode elements are shared as and are electrically connected to each other via a second air bridge line.

12. The light emitting device according to claim 11, wherein the first air bridge line and the second air bridge line are on opposite sides of the insulating substrate.

13. The light emitting device according to claim 7, wherein a negative electrode of one of the light emitting diode elements of the first set of light emitting diode elements, a positive electrode of one of the light emitting diode elements of the second set of light emitting diode elements, a positive electrode of one of the light emitting diode elements of the third set of light emitting diode elements, and a negative electrode of one of the light emitting diode elements of the fourth set of light emitting diode elements are shared as and are electrically connected to each other via an air bridge line.

14. The light emitting device according to claim 7, wherein a first negative electrode of a first light emitting diode element of the first group, a first positive electrode of a second light emitting diode element of the first group, a second positive electrode of a third light emitting diode element of the second group, and a second negative electrode of a fourth light emitting diode element of the second group are shared.

15. The light emitting device according to claim 14, where the first light emitting diode element, the second light emitting diode element, the third light emitting diode element, and the fourth light emitting diode element are disposed along an edge of the insulating substrate.

16. The light emitting device according to claim 7, wherein the plurality of light emitting diode elements are of approximately same shape and of approximately same size.

17. The light emitting device according to claim 7, wherein all light emitting diode elements of the first group of light emitting diode elements are connected in series between the two electrodes of the AC power supply.

18. The light emitting device according to claim 17, wherein all light emitting diode elements of the second group of light emitting diode elements are connected in series between the two electrodes of the AC power supply.

19. The light emitting device according to claim 7, wherein the negative electrode of one of the light emitting diode elements of the first set of light emitting diode elements is shared as and is electrically connected to a negative electrode of one of the light emitting diode elements of the third set of light emitting diode elements.

20. The light emitting device according to claim 7, wherein the first group and second group of light emitting diode elements each comprise at least three rows of light emitting diode elements.